Construction for a ski binding and a ski boot

ABSTRACT

A construction for a ski binding and a ski boot for coupling a ski boot ( 1 )—at its front section to a ski ( 2 ), and allowing the lifting of the heel section of the ski boot from the ski. The ski binding has a coupling mechanism ( 4 ) for coupling the ski boot to the binding, and the ski boot has a transverse rotation axis ( 5 ) coupled to the sole of the boot and positioned perpendicularly to the longitudinal direction of the sole, which rotation axis can be used for coupling the ski boot, with a locking mechanism, to an axial locking ( 6 ) provided on the ski, the sole of the ski boot including a toe section ( 7 ), a ball section ( 8 ), an arched section ( 9 ) and a heel section ( 10 ). The rotation axis is coupled to the sole of the boot such that the toe section is positioned in front of the rotation axis.

FIELD OF THE INVENTION

The invention relates to the construction for a ski binding and a ski boot for coupling the ski boot to the ski as defined in the preamble of claim 1.

BACKGROUND OF THE INVENTION

Known in cross-country skiing is a wide variety of different ski binding and ski boot constructions. What they all have in common is the coupling of the foot to the ski such that the kick power cannot be used to the maximum. Similarly, the natural functioning of the foot area has become almost impossible. An anatomically correct motion for a human is a rolling pace, such as during walking or running. In a natural advancement, the last parts of the foot area which touch the ground are thereby the toes, not the tips of the toes. In known ski bindings, this rolling motion has been prevented. Firstly, during the exertion phase, the movement of the foot has been so limited that the force which provides the grip to the exertion begins to decrease a moment before the final stage of the exertion, such that the ski may easily slip from under the foot. Secondly, the rolling motion of the foot area is prevented by a flexible element positioned in front of the boot, which limits the natural movement of the foot area for continuing the rolling pace.

A known technique in the field of the invention is disclosed for example in patent publication U.S. Pat. No. 5,228,714 which describes a ski binding for classic skiing style. The boot is coupled to the binding by means of a transverse coupling shaft which is substantially coupled to the tip of the boot. In different known bindings, this may be positioned slightly under the tip, just to the tip, or in front of the tip. The coupling shaft forms a support point between the boot and the ski right at the tip of the boot, such that only the tips of the toes contact the binding as the foot area rises. In practice, this causes the entire foot area being raised such that the controllability of the ski becomes unstable. Similarly, toward the final stage of the kick, as the heel rises, the pressure applied to the toes increases, causing pain and blackened toes. If instead one selects a larger boot, the controllability becomes even worse.

When the boot is coupled at the front section of the toes, the foot area rises during the final stage of the kick almost entirely off the ski. In this case, the kick force is transmitted almost entirely forward, and the force directed downward and providing the grip is left quite marginal. This results in the need for using grip wax on a relatively long portion along the length of the ski base.

Known from patent NO309845 is a ski binding in which the rotation point has been shifted backward under the toes. However, the construction comprises a wedge-shaped space which opens up and forward, in which space a flexible element is placed between the ski and the tip of the boot. If the toes reach up to the tip of the boot, they become bent upward in an unnatural position for effective skiing. The flexible element used in the wedge-shaped space limits the kick and directs forces to a wrong direction. Although the solution improves controllability, it has many deficiencies as to the production of force, and at the same time critically limits the natural movement of the foot area and the toes.

Due to the instable controllability, the binding constructions described above are not suitable for skate style skiing; instead a binding application has been developed therefore, manufactured by Salomon, wherein, in addition to the coupling at the front section of the toes, the boot is supported on the ski under the ball of the foot by means of a mechanism which limits the lifting of the boot from the ski to a specific angle. The application serves as a controlling construction, but it does not provide any appreciable improvement to correcting the direction of the kick. The same problems emerge in another binding developed for skate style skiing, manufactured by Rottefella, which seeks to obtain rigidity by modifying the rigidity of the flexible element positioned in front of the boot, and by reinforcement of the sole of the boot.

According to what has been presented above, the greatest problem of the ski bindings of the prior art, regardless of the skiing style, is their inability to provide an effective kick, which results from the wrong direction, timing, and duration of the kick forces. A further problem concerns movements which are unnatural to the anatomy of the human foot and complicate the control of the forces, prevent their effective use and cause injuries to skiers.

OBJECTIVE OF THE INVENTION

The objective of the invention is to eliminate the drawbacks referred to above.

One specific objective of the invention is to disclose a novel coupling of a ski boot to a ski binding, such that the kick force can be directed optimally, the force maintained as long as possible, and the movements of the foot with respect to the ski directed as naturally for the human foot as possible.

SUMMARY OF THE INVENTION

The construction for a ski binding and a ski boot in accordance with the invention is characterized by what has been presented in claim 1.

The construction for a ski binding and a ski boot in accordance with the invention is designed for coupling a ski boot from its front section to a ski and allowing the lifting of the heel section of the ski boot from the ski. The ski binding comprises a coupling mechanism for coupling the ski boot to the binding. The ski boot comprises a transverse rotation axis coupled to the sole thereof, the axis being perpendicular to the longitudinal direction of the sole, for coupling the ski boot by means of the coupling mechanism to an axial locking provided on the ski. The sole of the ski boot comprises a toe section, a ball section, an arched section, and a heel section. In accordance with the invention, the rotation axis is coupled to the sole of the boot such that the toe section of the sole of the boot is positioned in front of the rotation axis. Also according to the invention, the area under the toe section of the sole and in front of the rotation axis and the axial locking, below the horizontal plane defined by the rotation axis, comprises a substantially free space in which the toe section of the sole of the ski boot is able to bend down when the boot is bent about the rotation axis when lifting the heel section from the ski.

It should be noted that in this application, the rotation axis and the axial locking do not necessarily mean a concrete, straight and rigid axle and a corresponding groove; instead the terms should be understood as being used in the general sense. Therefore, the substantial feature is an articulated, rotating coupling between the sole of the boot and the soleplate or between the sole of the boot and the ski, which allows the rotation of the sole of the boot with respect to the ski or to the soleplate in a hinge-like manner about a specific, concrete or imagined, rotation axis.

In one embodiment of the invention, the substantially free space is formed by a recess formed in the soleplate and, therefore, possibly in the ski as well. In this case, the sole of the ski boot can be substantially linear in the longitudinal direction.

In a second embodiment of the invention, the substantially free space is formed partly by the shape of the soleplate and partly by the shape of the toe section in the sole of the boot.

In a third embodiment of the invention, the substantially free space is formed by a recess in the ski structure. In this case, it is, of course, also possible that the space is partly formed by the shape of the toe section of the sole.

The rotation axis may preferably be positioned 20-80 mm backwards from the front tip of the ski boot. In one embodiment, it is positioned at a distance of 30-60 mm from the front tip of the ski boot, the preferable distance being about 40-50 mm. It is, of course, natural that the above-mentioned distance cannot be set as a specific number of millimeters; instead it varies according to the skier's boot size, i.e. substantially according to the length of the skier's toes.

Therefore, the position of the rotation axis, as well as the limit between the toe section and the ball section, may be defined as being substantially under the first joint of the hallux of the skier's foot. Said limit may also be defined such that the toe section is the front section of the sole of the boot, to which the force applied downward by the toes is substantially entirely directed, i.e. more specifically, the area on which the three biggest toes are pressed as the heel is raised in the air.

In one embodiment of the invention, the rotation axis which is straight and perpendicular to the longitudinal direction of the ski and the sole of the ski boot cuts the arched line between the toe section and the ball section. Since the arched line, departing from the root of the hallux, arches backward toward the other edge, the areas covering the biggest toes in the toe section of the sole of the ski boot are positioned in front of the rotation axis. The pressing force of the skier's toes, i.e. the force applied from the skier's foot to the toe section of the sole, is thus directed downward mainly in front of the rotation axis.

The space in front of the rotation axis may be completely open, such that the toe section of the sole of the ski boot is able to freely bend in that area during a kick without any friction. In this case, however, the movement of the ski boot easily becomes insensitive and difficult to control. The space is, therefore, preferably only substantially open, i.e. free, i.e. a suitable elastic flexible element or other suitable elastic construction is placed therein, which element, when having a suitable contact to the bottom of the space and to the toe section of the sole of the ski boot, entirely prevents any frictionless or free bending of the boot.

Although any spring construction, bellow construction, air chamber, or other solution having sufficient flexibility can be used as the flexible element, it is preferably realized by means of a suitably elastic rubber or plastic element which, compressing for example for 50-80% and then reassuming its original shape, allows the ski boot to establish a sufficiently large rotation angle about its rotation axis.

The flexible element may fill the entire space, or it may be so formed that it covers only a portion of the space volume. It is also possible that it protrudes out of the space, but the portion protruding out is not substantially significant for the functioning of the flexible element. The protruding portion may be used, for example, for coupling the element to the ski binding.

One preferred embodiment of the invention comprises several flexible elements which can be coupled to the ski binding and differ from each other by their elastic properties. This enables the use of the same bindings in different skiing conditions and when skiing in both classic style and skate style just by changing a flexible element with different elastic properties to the binding.

Because the rotation axis used for locking the ski binding in accordance with the invention is not positioned at the tip of the boot, but instead clearly on the rear of the toe section, to some extent even on the ball area, the locking provides a significantly better and firmer horizontal torsional rigidity to the boot with respect to the ski than the traditional locking mechanisms right at the tip of the boot. Even so, one or more guiding ridges positioned along the length of the ski and directed backward from the axial locking can preferably be used on the soleplate. These ensure, especially in skate style skiing, that the boot is held in place during the start phase of the kick.

In the construction for a ski binding and a ski boot in accordance with the invention, the substantial feature is that the front section of the boot, i.e. the toe section of the sole, bends down and moves substantially in a vertical direction in front of the locking of the boot, i.e. the rotation axis. The lever formed by the toe section in front of the rotation axis can be pressed down by the toes during normal, natural skiing to intensify the increase in pressure caused by the bending of the boot. This results in achieving a significantly more effective pressure between the ski and the snow than with the known solutions, and at the same time obtaining a better and easier grip than before. In this solution, the entire grip zone of the ski is in contact with snow also during the final phase of the kick, providing a better grip than with the known constructions.

In the construction in accordance with the invention, the free space formed under the front section of the boot, i.e. the toe section, allows the front section of the foot, i.e. the toes, to be pressed below the rotation axis, enabling therefore the establishment of a rolling pace for the first time in the history of skiing. The movement of the foot in this case is natural, and even when moving in a walking-like manner, the grip zone of the ski is efficiently pressed against snow, improving even further the grip of a grip-waxed ski. The movement of the foot directs the force efficiently and correctly.

Compared to prior art, the binding construction in accordance with the invention has many significant advantages: it is firmer and therefore safer; it has a better controllability; it provides a better and more precise grip, so that the grip zone of the base can be shortened and the slide zone lengthened; the improved sliding saves energy; due to better controllability, the ankle joints do not become stressed; a more effective use of the foot area and toes adds power to the kicks and improves blood circulation in the foot area; the increased force and more optimal direction of the kick improve skiing efficiency; and the same binding construction can also be used, only by changing the elastic element, in boots of different sizes, in cross-country skiing and skate style skiing, as well as in touring and telemark skiing. The binding construction in accordance with the invention provides a natural way of moving on skis, and a more effective and firmer kick, thus saving energy for the skier.

LIST OF FIGURES

In the following, the invention will be described in detail by means of examples with reference to the accompanying drawings, in which

FIG. 1 represents a schematic side view of one ski binding and ski boot in accordance with the invention,

FIG. 2 represents a more detailed top view of the embodiment of FIG. 1,

FIG. 3 represents a more detailed side view of the embodiment if FIG. 1,

FIG. 4 represents a schematic side view of one embodiment of the invention,

FIG. 5 represents a schematic side view of a second embodiment of the invention,

FIG. 6 represents a schematic side view of a third embodiment of the invention,

FIG. 7 represents a schematic side view of the fourth embodiment of the invention,

FIG. 8 represents a power curve indicating the efficiency of the invention in skate style skiing, and

FIG. 9 represents a power curve indicating the efficiency of the invention in classic style skiing.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 represents a schematic side view of the construction for a ski boot and a ski binding in accordance with the invention. A soleplate 3 of the ski binding is coupled to a ski 2, the front section of which soleplate comprises a coupling mechanism 4, such as a push button, a lever mechanism, a compression spring, or some other known construction, for coupling a ski boot 1 to the binding. The ski boot 1 is coupled at the sole to the ski binding, the sole being formed, in the order backwards from the tip, by a toe section 7, a ball section 8, an arched section 9 and a heel section 10. An axis which is transverse with respect to the longitudinal direction of the ski, i.e. a rotation axis 5, is coupled substantially at the junction of the toe section 7 and the ball section 8 to the sole of the ski boot for coupling the ski boot to the soleplate 3. The corresponding position on the soleplate 3 comprises an axial locking 6, a construction known in the art per se, wherein a groove which is shaped to correspond to the rotation axis comprises locking shoulders which hold the axis in place in the groove. The locking shoulders are connected in a known manner to the coupling mechanism on the front section of the ski binding, from which coupling mechanism the locking can be opened for example by pushing a button.

FIGS. 2 and 3 comprise a more detailed description of the ski binding and the functioning thereof in accordance with one embodiment of the invention. The binding comprises a soleplate 3 for the ski binding, which soleplate is coupled to a ski 2, the front section of the soleplate comprising a coupling mechanism 4 which is connected, via a coupling 18 indicated in dashed line, to an axial locking 6, positioned farther back in the binding. The locking is formed by a partially open-top groove in which a straight axis stub of a suitable size can be pressed to a locked-up position.

The area on the soleplate 3 between the axial locking 6 and the coupling mechanism 4 is mainly formed as a straight surface 19 which slopes down toward the coupling mechanism, both edges of which surface comprising on the soleplate even and horizontal rims 20. On the straight sloping-down surface 19, a wedge-shaped flexible element 15 of substantially the size of the surface is placed, which element is made from a suitable elastic material, for example rubber. One edge of the flexible element 15 is positioned near the axial locking 6, from which the element extends forward towards the coupling mechanism 4, growing in diameter as it extends, the growth being stronger than the downward sloping of the surface 19. The upper surface of the flexible element 15 is thereby formed to slope upwards from the axial locking 6 toward the coupling mechanism 4.

The front section of the sole of the boot 1 which is coupled to the ski binding comprises the toe section 7 and the ball section 8. The toe section 7 of the sole is bent somewhat upward, such that it is parallel to the upper surface of the flexible element 15 and rests against it, whereas the ball section 8 is parallel to the soleplate 3 of the binding. A transverse rotation axis 5 is coupled to the area between the toe section and the ball section on the sole of the ski boot, which axis can be pressed and locked in the corresponding groove in the axial locking 6. The locking can be released by means of a press or a lever, not shown in the figure in any detail, provided in the coupling mechanism 4.

The construction for a ski binding and a ski boot in accordance with the invention increases, during the kick phase, in both skate and classic styles, the production of force to the rotation point, because the leverage of the toe section directs the force to the right direction, i.e. more downward. This improves the production and direction of force, and the maneuverability and control of the ski, compared to the prior art.

During skiing, the toe section 7 of the sole in front of the rotation axis 5 reacts to the elasticity of the flexible element 15, applying the moment of force, which results from the distance between the rotation axis and the tip of the boot, to the ski. A kick in classic skiing is thus applied downward, pressing the central area of the ski to the ground and resulting in a mechanical grip. The increased force caused by the moment improves the ski grip and provides the grip to the kick at an earlier phase. In skate style, the construction provides an advancing kick, furthering the sliding of the ski for example on the flat and during climbing. At the same time, the increased contact surface area between the boot and the binding provides a better control to different phases of skiing in all horizontal and vertical directions.

FIG. 4 represents an embodiment of the invention in which the substantially free space under the toe section of the ski boot is formed solely on the soleplate 3 of the ski binding by shaping it to evenly slope down and forward, from the axial locking 6 to the coupling mechanism 4 of the binding. It this case, the toe section and the ball section of the sole of the boot are straight and parallel with each other.

FIG. 5 represents an embodiment of the invention in which the substantially free space under the toe section of the ski boot is formed as in FIG. 4 on the soleplate 3 of the ski binding by shaping it to slope down and forward from the axial locking 6, but here also the toe section of the sole of the boot is shaped to slope slightly upward toward the tip of the boot. However, the shape of the soleplate forms, in this embodiment as well, the most significant space for the movement of the tip of the boot.

FIG. 6 represents an embodiment of the invention in which the substantially free space 13 under the toe section of the ski boot has a horizontal bottom. In this case, the toe section of the sole of the ski boot is straight and substantially parallel to the other sections of the sole.

FIG. 7 represents an embodiment of the invention in which the substantially free space 21 is formed on the ski 2. The wedge-shaped space 21 which slopes down and forward on the ski, together with the slight upward bending of the toe section of the sole of the boot, form a space which opens and extends forward from the coupling point of the sole of the boot, in which space the tip of the boot, i.e. the toe section, is able to bend during the kick phase when skiing. In this embodiment, the coupling mechanism 4 is coupled to the ski and is part of the ski, so that the axial locking at the back edge of the wedge-shaped space 21 are connected to the coupling mechanism 4 via the ski construction. Flexible elements of different materials and different shapes can be used in this embodiment as well to provide the desired bending properties to the boot.

FIG. 1 represents the embodiment in which the wedge-shaped space is open and empty. In FIG. 3, the wedge-shaped space is completely filled with the elastic flexible element 15. In FIG. 4, the elastic flexible element 16 extends, as an evenly wide construction, laterally throughout the entire wedge-shaped space 12, but along the length of the ski only to the central area of the wedge-shaped space. In the embodiment of FIG. 5, the flexible element 16 extends from the tip of the wedge-shaped space 14, i.e. from the rotation axis, approximately to the mid point of the length of the wedge-shaped space along the length of the ski. In the embodiment of FIG. 6, the flexible element 16 is positioned in the center of the wedge-shaped space 13 as in FIG. 4, but here the flexible element tapers upwards so that the flexible properties thereof can be adjusted as desired.

FIGS. 8 and 9 represent measurement results of a comparison between bindings in accordance with the prior art and the binding in accordance with the invention in skate style, FIG. 8, and in classic style, FIG. 9. The curves indicate the force applied to the grip zone of the ski during the kick phase, i.e. when a grip is needed, as a function of time. The lower curve, or the dark area, in the figures represents the traditional binding, and the upper curve represents the solution in accordance with the invention.

As can be seen from FIG. 8, in free style skiing, the force used for a kick, which lasts for about one second, increases toward the end of the kick. For the first half of the second, the forces are nearly equal, but during the latter half of the kick, the boot in the traditional binding begins to bend just about its tip, so that it becomes difficult to increase the force. However, in the binding in accordance with the invention, the toe section bends in front of and below the rotation axis during the final phase of the kick, so that the kick force applied to the ski increases significantly faster, becomes significantly stronger and lasts significantly longer than with traditional bindings.

According to FIG. 9, in classic skiing style the kick forces applied to the ski are equal for only about ⅓ of the total length of the kick. After this, the flexible part in front of the boot in traditional bindings unexpectedly causes, as the boot starts to bend and the flexible part starts to compress, an instantaneous decrease in the kick force, after which it starts to rise again and reaches its maximum value at about 0.7 seconds, descending steadily thereafter at the end of the kick. The invention, however, does not produce any kind of temporary decrease in the kick force; instead the kick force increases relatively linearly to reach the maximum level which is about 20% greater than with the prior art, and descends rapidly only after about 0.85 seconds.

The figures show clearly that with the binding construction in accordance with the invention, the kick force is, at least for about half of the kick duration, significantly greater, and for about ⅓ of the kick duration at a higher level than the relatively narrow peak that can be reached at the maximum with the traditional binding. In addition, a relevant and unexpected feature in the invention is that the results described above can be obtained both in racing and in relaxing recreational skiing, without any specific measures or any effort to learn anything, because the inventive binding construction and the functioning thereof are based on the natural anatomy and functioning of the foot.

The invention is not limited merely to the examples of its embodiments referred to above; instead many variations are possible within the scope defined by the claims. 

1. A construction for a ski binding and a ski boot for coupling a ski boot (1) at its front section to a ski (2), and allowing the lifting of the heel section of the ski boot from the ski, which ski binding comprises a coupling mechanism (4) for coupling the ski boot to the binding, and which ski boot comprises a transverse rotation axis (5), coupled to the sole of the boot and positioned perpendicularly to the longitudinal direction of the sole, which rotation axis can be used for coupling, by means of the coupling mechanism, the ski boot to an axial locking (6) provided on the ski, the sole of the ski boot comprising a toe section (7), a ball section (8), an arched section (9) and a heel section (10), characterized in that the rotation axis (5) is coupled to the sole of the boot such that the toe section (7) is positioned in front of the rotation axis, and in that the area under the toe section (7) of the sole and below the horizontal plane defined by the rotation axis (5) comprises a substantially free space (11) in which the toe section of the sole is able to bend down as the boot is bent about the rotation axis when lifting the heel section (10) from the ski.
 2. The construction for a ski binding and a ski boot according to claim 1, characterized in that the ski binding comprises a soleplate (3), and in that the substantially free space (11,12) is formed by a recess formed on the soleplate.
 3. The construction for a ski binding and a ski boot according to claim 1, characterized in that the substantially free space (11,14) is formed partly by the shape of the soleplate and partly by the shape of the toe section of the sole of the boot.
 4. The construction for a ski binding and a ski boot according to claim 1, characterized in that the substantially free space (21) is formed by a recess formed on the ski (2).
 5. The construction for a ski binding and a ski boot according to claim 1, characterized in that the substantially free space (11,14) is formed partly by the shape of the ski and partly by the shape of the toe section of the sole of the boot.
 6. The construction for a ski binding and a ski boot according to claim 1, characterized in that the rotation axis (5) is positioned 20-80 mm, preferably 30-60 mm, for example about 40-50 mm backward from the front tip of the ski boot.
 7. The construction for a ski binding and a ski boot according to claim 1, characterized in that the rotation axis (5) is positioned under the first joint of the hallux of the skier's foot.
 8. The construction for a ski binding and a ski boot according to claim 1, characterized in that the substantially free space (11) comprises an elastic flexible element (15,16).
 9. The construction for a ski binding and a ski boot according to claim 8, characterized in that the flexible element (15) fills the entire space.
 10. The construction for a ski binding and a ski boot according to claim 8, characterized in that the flexible element (16) covers only a portion of the space volume.
 11. The construction for a ski binding and a ski boot according to claim 1, characterized in that the substantially free space is wedge-shaped and in that the height of said space increases forward.
 12. The construction for a ski binding and a ski boot according to claim 1, characterized in that the ski binding comprises several interchangeable flexible elements with different elastic properties.
 13. The construction for a ski binding and a ski boot according to claim 1, characterized in that the soleplate (3) comprises one or more guiding ridges (17) in the longitudinal direction of the ski (2), which ridges extend backwards from the axial locking (6). 